This patch fixes bug 243131: Can't mount GFS2 file system on AoE device.
When using AoE devices with lock_nolock, there is no locking table, so
gfs2 (and gfs1) uses the superblock s_id. This turns out to be the device
name in some cases. In the case of AoE, the device contains a slash,
(e.g. "etherd/e1.1p2") which is an invalid character when we try to
register the table in sysfs. This patch replaces the "/" with underscore.
Rather than add a new variable to the stack, I'm just reusing a (char *)
variable that's no longer used: table.
This code has been tested on the failing system using a RHEL5 patch.

The upstream code was tested by using gfs2_tool sb to interject a "/"
into the table name of a clustered gfs2 file system.